A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section.
A significant amount of propulsive thrust is produced by bypass airflow through a bypass flow passage. The bypass flow passage is defined between an outer fan nacelle and an inner core nacelle. The outer nacelle includes an aft end portion that defines a fan nozzle. Low fan pressure engines typically need fan nozzle area growth at maximum take-off thrust conditions. Moreover, the fan nozzle is desired to provide a growth area at the maximum take-off thrust that manages fan flutter at the low fan pressures.
Although geared architectures have improved propulsive efficiency, turbine engine manufacturers continue to seek further improvements to engine performance including improvements to thermal, transfer and propulsive efficiencies.